BACKGROUND:

The Wnt/β-catenin pathway regulates intestinal development, homeostasis, and regeneration after injury. Wnt/β-catenin signaling drives intestinal proliferation by activating expression of the c-Myc proto-oncogene (Myc) through the Myc 3' Wnt responsive DNA element (Myc 3' WRE). In a previous study, we found that deletion of the Myc 3' WRE in mice caused increased MYC expression and increased cellular proliferation in the colon. When damaged by dextran sodium sulfate (DSS), the increased proliferative capacity of Myc 3' WRE(-/-) colonocytes resulted in a more rapid recovery compared with wild-type (WT) mice. In that study, we did not examine involvement of the immune system in colonic regeneration.

PURPOSE:

To characterize the innate immune response in Myc 3' WRE(-/-) and WT mice during and after DSS-induced colonic injury.

METHODS:

Mice were fed 2.5 % DSS in their drinking water for five days to induce colonic damage and were then returned to normal water for two or four days to recover. Colonic sections were prepared and neutrophils and macrophages were analyzed by immunohistochemistry. Cytokine and chemokine levels were analyzed by probing a cytokine array with colonic lysates.

RESULTS:

In comparison with WT mice, there was enhanced leukocyte infiltration into the colonic mucosal and submucosal layers of Myc 3' WRE(-/-) mice after DSS damage. Levels of activated neutrophils were substantially increased in damaged Myc 3' WRE(-/-) colons as were levels of the neutrophil chemoattractants C5/C5a, CXCL1, and CXCL2.

CONCLUSION:

The Myc 3' WRE regulates neutrophil infiltration into DSS-damaged colons.

PURPOSE:

We investigated expression of TM4SF5 and its involvement in human esophageal cancer (HEC).

METHODS:

We analyzed TM4SF5 expression in normal esophageal epithelial cells (HEEC), in four HEC cell lines, and in 20 HEC clinical tissue samples and matched nontumor samples. The effect of TM4SF5 on HEC cell proliferation and metastasis and invasion was assessed, and the relationship between TM4SF5 and integrin β1 was determined. Finally, TM4SF5 and integrin β1 expression were further examined by use of immunohistochemistry (IHC) and tissue microarray analysis, and the prognostic use of TM4SF5 and integrin β1 in HEC was evaluated.

RESULTS:

TM4SF5 was more highly expressed in HEC cells and in HEC tissues than in HEEC and matched nontumor tissues. Down-regulation of TM4SF5 in KYSE150 cells reduced cell proliferation and metastasis and invasion whereas metastasis and invasion by KYSE510 increased after TM4SF5 cDNA transfection. In HEC cells, TM4SF5 formed a complex with integrin β1, and interference with integrin β1 in KYSE510-TM4SF5 cells markedly inhibited cell invasion on laminin 5. Our findings also showed that TM4SF5 and integrin β1 overexpression correlated with low differentiation and high stage (p < 0.05, respectively). Postoperative 5-year overall survival of patients with TM4SF5(low) and/or integrin β1(low) was higher than for patients with TM4SF5(high) and/or integrin β1(high). Multivariate analysis demonstrated that TM4SF5 and integrin β1 co-overexpression was an independent prognostic marker for HEC.

CONCLUSION:

TM4SF5 is positively associated with HEC invasiveness. The combination of TM4SF5 with integrin β1 could potentially serve as a novel marker for predicting HEC prognosis.

BACKGROUND:

There are limited data on the effect of endoscopic mucosal resection (EMR) on changes of histopathologic diagnosis for Barrett's esophagus (BE) patients undergoing endoscopic eradication therapy (EET); especially those without visible lesions.

AIM:

To compare the frequency of changes of diagnosis by EMR compared with pre-EMR biopsy diagnosis for patients with and without visible lesions.

METHODS:

In this multicenter outcomes project, patients with Barrett's-related neoplasia undergoing EET at three tertiary-care centers were included. Patients undergoing biopsies followed by EMR within six months were included. The main outcome measures were frequency of overall change of histopathologic diagnosis, change based on pre-EMR biopsy diagnosis, and change based on the presence of visible lesions.

RESULTS:

One-hundred and thirty-eight BE patients (low-grade dysplasia (LGD) 15 (10.9 %), high-grade dysplasia (HGD) 87 (63 %), esophageal adenocarcinoma (EAC) 36 (26.1 %)) were included; 114 (82.6 %) patients had visible lesions. EMR resulted in a change of diagnosis for 43 (31.1 %) patients (upgrade 14 (10.1 %); downgrade 29 (21 %)). For HGD patients, EMR downstaged dysplasia grade for 17 (19.5 %) cases and upstaged it to EAC for nine (10.3 %) cases. There was a change of diagnosis for 26 (29.9 %) HGD patients, irrespective of the presence or absence of visible lesions (p = 0.76). For EAC patients, EMR downstaged dysplasia grade in 10 (27.8 %) cases. There was a change of diagnosis for 10 (27.8 %) EAC patients, irrespective of the presence or absence of endoscopically visible lesions (p = 0.48).

CONCLUSIONS:

EMR results in a change of diagnosis for approximately 30 % of BE patients with early neoplasia (with and without visible lesions) referred for EET.

BACKGROUND AND AIM:

Neutrophil gelatinase associated lipocalin (NGAL) is a recently identified molecule, which is bacteriostatic, has tissue destructive effects and is pro-inflammatory with chemoattractant molecule binding properties. Our aim was to investigate the relationship between serum NGAL levels and the type and level of disease activity of IBD.

METHODS:

A total of 92 patients [43 with Crohn's disease (CD) and 49 with ulcerative colitis (UC)], and 30 age- and sex-matched healthy controls (HC) were included in this study. Serum NGAL levels were measured using ELISA.

RESULTS:

Serum NGAL levels were elevated in the IBD group [median 171, range (57-312) ng/mL] compared to the HC group [107 (45-234) ng/mL] (p < 0.0001) and were elevated in UC patients [188 (74-312) ng/mL] compared to CD patients [168 (57-279) ng/mL] (p = 0.006). When NGAL levels were further analysed based on localization of the CD and UC, the levels in ulcerative pancolitis [233 (144-312) ng/mL] were significantly higher (p = 0.004) than the left-sided colitis [156 (103-309) ng/mL]. Similarly, NGAL levels were significantly higher in colonic CD [207 (125-249) ng/mL] than ileal CD [114 (78-210) ng/mL], and also in ileocolonic CD [198 (57-279) ng/mL] than ileal CD (p = 0.033). When CD and UC groups were further categorized as active and inactive according to clinical and endoscopic activity indices, serum NGAL concentrations did not differ between inquiescent versus active stages. When a cut-off level of 129 ng/mL was used to distinguish IBD from HC, a sensitivity of 76.1 % and a specificity of 60.9 % was reached.

CONCLUSIONS:

The serum NGAL levels in the IBD group was significantly higher than the HC group. Serum NGAL levels were higher in more extensive colonic involvement.

BACKGROUND:

Intestinal absorptive capacity shows a circadian rhythm synchronized with eating patterns. Disrupting these coordinated rhythms, e.g., with shift work, may contribute to metabolic disease. Circadian expression of nutrient transporters has not been studied in metabolic disease. We studied the circadian rhythm of intestinal transporter sodium glucose co-transporter type 1 (SGLT1) in an obese diabetic rat.

METHODS:

We compared obese Zucker diabetic fatty (ZDF) rats to lean ZDF littermates. Temporal feeding patterns were assessed, then rats were harvested at Zeitgeber (ZT, ZT0 = 7:00 a.m.) 3, 9, or 15 to measure insulin resistance, SGLT1 expression and intestinal glucose absorption capacity. Regulators of SGLT1 (sweet taste receptor T1R2/3; clock genes) were measured to elucidate underlying mechanisms.

RESULTS:

Both groups exhibited altered circadian food intake. Obese ZDF rats lost circadian rhythmicity of SGLT1 mRNA expression and functional activity. Lean ZDF rats maintained rhythmicity of SGLT1 mRNA expression but that of functional glucose absorption was blunted. Circadian rhythms of intestinal clock genes were maintained in both groups. Neither group had discernible rhythms of intestinal GLUT2 (glucose transporter) or T1R2 (sweet taste receptor component) mRNA expression. In summary, lean and obese ZDF rats exhibited similar disruptions in circadian feeding. Glucose intolerance was evident in lean rats, but only obese rats further developed diabetes and exhibited disrupted circadian rhythmicity of both SGLT1 mRNA expression and function.

CONCLUSIONS:

Our findings suggest that disrupted circadian feeding rhythms contribute to glucose intolerance, but additional factors (genetics, changes in nutrient sensing/transport) are needed to lead to full diabetes.

OBJECTIVES:

The study used a model of 90 % portal branch ligation (PBL) in rats to study the effect of losartan on portal vein pressure (PVP) and liver regeneration in rats after PBL.

METHODS:

A total of 144 male Sprague-Dawley rats were arbitrarily designated into three treatment method groups: a sham operation group (Sham), a PBL treatment group (PBL), and a PBL plus losartan treatment group (PBL + L). Losartan (2 mg/day) was intragastrically gavaged 3 days before the PBL or sham operation to time points of study.

RESULTS:

Both the PBL and PBL + L groups showed an intense surge in PVP after PBL treatment, peaking at 12 h postsurgery, then lessening progressively afterwards. PVP was substantially greater in these two groups compared with the Sham group at 6-72 h postsurgery (p < 0.01). Compared with the PBL group, the PBL + L group showed a noticeable reduction in PVP 6-48 h postsurgery (p < 0.05); the PBL group showed considerably raised levels of plasma ALT and AST 6-72 h postsurgery (p < 0.01). Compared to the PBL group, the PBL + L group showed drastically reduced plasma ALT and AST levels 12-72 h postsurgery (p < 0.05).

CONCLUSIONS:

Losartan supports liver regeneration in 90 % of rats that underwent PBL. The mechanism may be related to losartan's ability to regulate PVP and increase serum hepatocyte growth factor levels.

BACKGROUND:

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer deaths worldwide. It is important to understand molecular mechanisms of HCC progression and to develop clinically useful biomarkers for the disease.

AIM:

We aimed to investigate the possible involvement of α-tubulin1b (TUBA1B) in HCC pathology.

METHODS:

Tissue specimens were obtained from 114 HCC patients during hepatectomy. Immunohistochemistry and western blot analysis were used to detect TUBA1B expression in HCC tissues and cell lines. TUBA1B was knocked down in HCC cells by siRNA transfection. CCK-8 assay and flow cytometry were applied to determine cell proliferation and cell cycle progression, respectively. The efficacy of paclitaxel chemotherapy was evaluated by plate colony formation assay.

RESULTS:

TUBA1B was higher expressed in HCC tumor tissues than in adjacent nontumor tissues. TUBA1B and Ki-67 expressions were positively related to each other, and both their expressions were significantly associated with histological grade of HCC patients. Univariate and multivariate survival analyses revealed that TUBA1B was a significant predictor for overall survival of HCC patients. TUBA1B expression was increased in HCC cells during the G1- to S-phase transition. TUBA1B knockout in HCC cells inhibited cell proliferation, and attenuated resistance to paclitaxel.

CONCLUSIONS:

Our results indicated that TUBA1B expression was upregulated in HCC tumor tissues and proliferating HCC cells, and an increased TUBA1B expression was associated with poor overall survival and resistance to paclitaxel of HCC patients.

BACKGROUND:

Many herbal dietary supplements (HDS) contain green tea extract (GTE) and its component catechins, although their presence may not always be indicated on the product label.

PURPOSE:

Because GTE and catechins have been implicated in human hepatotoxicity in several case reports, our objective was to determine whether catechins were present in HDS that were implicated in hepatotoxicity, even if not identified among the labeled ingredients, and whether these compounds could be associated with liver injury.

METHODS:

We assayed 97 HDS implicated in human hepatotoxicity for catechins.

RESULTS:

We found that 29 of 73 HDS (39.7 %) that did not identify GTE or any of its component catechins on their label contained catechins. Among patients with confirmed hepatotoxicity, there was no statistically significant association between the presence of catechin or the dose consumed and liver injury causality score, severity, or pattern of liver injury. Catechin levels tended to be highest in products used for weight loss, although catechin concentrations were low in most products.

CONCLUSIONS:

Many HDS commonly contain catechins that are implicated in hepatotoxicity, although their presence may not be indicated on the product label. Although our results did not establish an association between GTE or catechins with hepatotoxicity, they highlight some of the many complexities and uncertainties that surround the attribution of drug-induced liver injury (DILI) to HDS.